Atomic structure

Question 1

Element

Answer 1

• a substance containing only one type of atom
• all the atoms in an element have the same proton number

Question 2

Atom

Answer 2

the smallest part of an element that can take part in a chemical change

Question 3

Proton

Answer 3

positively charged particle in the nucleus of an atom

Question 4

Neutron

Answer 4

uncharged particle in the nucleus of an atom

Question 5

Electron

Answer 5

negatively charged particle found in orbitals outside the nucleus of an atom ; negligible mass

Question 6

Energy levels

Answer 6

the specific distances from the nucleus corresponding to the energy of the electrons

• electrons in energy levels further from the nucleus have more energy than those closer to the nucleus

Question 7

What are the three main subatomic particles, and what are their charges and relative masses?

Answer 7

Proton: Charge: +1, Relative Mass: 1
Neutron: Charge: 0, Relative Mass: 1
Electron: Charge: -1, Relative Mass: 1/1836

Question 8

What are isotopes?

Answer 8

Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons, resulting in different mass numbers.

Question 9

What is ionisation energy ?

Answer 9

Ionisation energy is the energy required to remove one mole of electrons from one mole of gaseous atoms.

Question 9

Factors affecting ionisation energy

Answer 9

• nuclear charge
• atomic radius
• shielding effect
• spin pair repulsion

Question 10

Explain why successive ionisation energies increase.

Answer 10

because removing an electron from a positively charged ion requires more energy due to the stronger attraction between the nucleus and remaining electrons.

Question 11

Describe the shapes of the s, p, and d orbitals.

Answer 11

s-orbital: Spherical shape.
p-orbital: Dumbbell shape.
d-orbital: Complex, cloverleaf shape.

Question 12

What is electron affinity ?

Answer 12

Electron affinity is the energy change when one mole of electrons is added to one mole of gaseous atoms to form one mole of negative ions.

Question 13

How does ionisation energy change across a period ?

Answer 13

Ionisation energy increases due to increasing nuclear charge.

Question 14

How does ionisation energy change down a group ?

Answer 14

Ionisation energy decreases due to increased shielding and atomic radius.

Question 15

What is the shielding effect?

Answer 15

The shielding effect is the reduction in the effective nuclear charge on the electron cloud due to the repulsion of electrons in inner shells.

Question 16

How do atomic and ionic radii change across periods and down groups?

Answer 16

Across a period: Atomic and ionic radii decrease due to increasing nuclear charge.

Down a group: Atomic and ionic radii increase due to the addition of electron shells

Question 17

What is the purpose of mass spectrometry in atomic structure?

Answer 17

Mass spectrometry is used to determine the relative abundance of isotopes and the relative atomic mass of elements

Question 18

Orbital

Answer 18

a region in space where up to 2 electrons can be found

Question 19

Principal quantum number (n)

Answer 19

represents the shell that the electrons occupy